I converted my V8 3.9 EFI Discovery 1 last year. The car has preformed beautifuly up untill two months ago. Since then I have changed coil leads plugs distributor sensors to no avail. My problem manifests it's self when car is run up to tempreture. At this point her reves rais on gas as well as petrol. Though the petrol runs very sick and somtimes will not rev from idle and when stopped she will not start for 30 mins. I have cleaned stepper motor, changed air filter and checked all the usual suspects that I know of and been told. I took it back to the gas fitter and he could not help. I need a mechanical guru!
Can anyone help me? Thanks!